const EventEmitter = require('events').EventEmitter;
function Dog(name, energy){
  let _name = name,
      _energy = energy,
      that = this;
  EventEmitter.call(this);

  let timer = setInterval(()=>{
 
    if(_energy > 0){
      that.emit('bark');
      _energy--;
    }else{
      clearInterval(timer);
    }
  }, 1000);
  this.name = ()=>_name;
  this.energy = ()=>_energy;
}
Dog.prototype = EventEmitter.prototype;
module.exports = Dog;
